MachIVshooter
Member
The M33 .50BMG pushes a 668gr fmj down the tube to 2910fps hitting 12,550ft.lbs energy at the muzzle, but the recoil energy from it is somewhere in the 70ft.lb. neighborhood. Is the rest soaked up by the rifle?
Yes. It's the same concept vis a vis a rocket not pushing the earth out of orbit. .50 BMG rifles are heavy, usually ~ 30 lbs. That's 210,000 grains, or 314 times what the bullet weighs. While the calculation for free recoil is a little more complicated than using the weight differential factor applied to muzzle energy, it is not difficult to understand why the recoil energy is exponentially lower than the projectile energy.
If the bullet had the same mass as the gun & cartridge case, they'd both depart their static location at the same speed, in opposite directions.